Fault probability and time domain simulation quasi-steady-state-based successive fault online evaluation method

Abstract

The invention discloses a successive fault online evaluation method based on fault probability and time domain simulation quasi-steady state. The equipment fault probability, the fault position and the fault type are given based on external meteorological disaster evaluation; generating a successive fault sequence according to the equipment fault probability or manual assignment; for each successive fault sequence, according to an equipment fault sequence, a control protection model of the direct current system, a second three-defense line control strategy, new energy off-network protection and an alternating current and direct current equipment protection model are considered; quasi-steady-state operation mode judgment and safety and stability and accident event level risk assessment after equipment faults are carried out based on time domain simulation, quasi-steady-state power flow stability calculation data are generated to be used for online safety and stability and accident eventlevel risk assessment of subsequent successive equipment faults, and the accuracy of successive fault assessment is improved. The method provided by the invention provides effective technical supportfor identifying key links of high-risk successive faults and blocking evolution of the successive faults in actual power grid operation.

Description

technical field [0001] The invention belongs to the technical field of electric power system automation, and in particular relates to an on-line evaluation method for sequential faults based on fault probability and time-domain simulation quasi-steady state. Background technique [0002] The load of the power system is constantly increasing, the transmission distance is gradually increasing, its scale is constantly expanding, and its structure is becoming more and more complex. The uncertainties brought about by the commissioning of a large number of flexible AC transmission and UHVDC transmission projects and large-scale access to new energy have made the dynamic characteristics of modern power systems more and more complex. At the same time, the impact of the external weather environment on the power grid is gradually deepening Natural disasters occur frequently, and the safety of equipment and the safe and stable operation of the power grid are facing major challenges. I...

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Problems solved by technology

Affected by factors such as disaster type and geographical environment, equipment failures are uncertain at all times, but researchers usually assume that multiple equipment failures occur at the same time, and evaluate the transient state and dynamic security and stability of the power grid based on the form of group failures, ignoring the equipment failure interval time In the long case, the accuracy of the evaluation results cannot meet the requirements. The existing sequential fault evaluation method based on pure power flow calculation is difficult to take into account the third line of defense control, new energy off-grid, DC continuous commutation failure leading to blocking, AC and DC The impact of equipment protection action, the accuracy can not meet the requirements

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